5. THYMUS Or THYROID

6. DDx Thymus:Thymic carcinoma papillary variant
Thyriod(retrosternal or metastatic): Papillary carcinoma with poorly differentiated squamous foci

7. Papillary thymic carcinoma:
This tumor resembles papillary thyroid carcinoma by virtue of the complex arborizing structure and the presence of psammoma bodies. However, it lacks optically clear nuclei, it is positive for CD5, and it shows no reactivity for thyroglobulin or TTF-1 Most of the reported cases have arisen from type A (spindle cell, medullary) thymomas

8. thyroglobulin

9. thyroglobulin

10. TTF-1

11. TTF-1

12. CD5

13. CD5

14. CD5